Power Out From Electric Space Heater

I ran my electric space heater this morning and the power went out on that circuit. I checked the breakers and none had tripped. I reset all the breakers, but still no power on that circuit. I have three GFI's, but none of them are tripped, and they are on a different circuit anyway.

I've unplugged everything and still no power, but no tripped breakers.

Could a breaker be bad, even though it resets like all the other breakers and feels locked into the "on" position?

The available voltage can be tested at the breaker. It is very possible that you had a poor connection somewhere which has now burnt, causing a lack of continuity. This could be a fire hazard, and any loads should be removed from the circuit until it is properly diagnosed.

That was going to be my first question. It is also the easiest thing to check and isolates the problem to the heater OR the circuit. There are many things that can cause a circuit to go bad, starting with a burned out breaker, or a breaker with a "melted" connection the bus bar, going all the way to a bad outlet. NO way for us to diagnose it without being there and doing our own testing.

The portable electric heater is fine. It's working perfectly on another circuit and has never overheated.

The breaker is also good. There is power coming out of it. And whatever is going on does not trip the breaker. But there is no power making it to any of the devices on that circuit, which includes three outlets, one light switch and one stacked light switch.

There are no loose wires or evidence of burning on any device.

I replaced all three outlets anyway, since they were very old.

Behind the stacked switch, there were several hot wires pig-tailed together and wrapped with dried-out electrical tape. I removed the tape and checked for loose wires and voltage. No loose wires and no power making it to those wires either. I re-taped the connections.

Above the breaker box is the access panel to the attic. I suppose the next step is to go up there and check for a break in the romex. Maybe an animal chewed through something. But that wouldn't explain why the power went out after the heater was running for a few minutes. You would think if an animal had severed the romex, the heater would not have gone on at all.

If there is no obvious break or burnt-out connection in the attic, what is the quickest way to find the source of the problem if it's in the wall somewhere?

I really don't like taped (only) connections...get yourself a properly sized wire nut. Twisting wires together just isn't a great way to make a connection. If any of the receptacles are using a friction, rear-stab connection (the ones with clamps and a screw are fine), you might want to consider using receptacles with better connections, or pigtail them and then make a connection to the screws only.

But that wouldn't explain why the power went out after the heater was running for a few minutes.

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There is no doubt in my mind that the biggest problem is the heater itself. It wouldn’t matter if the receptacles and switches were installed using the stab-loc method or not.
The biggest cord and plug load that can be plugged into any 15 amp receptacle is 1440 watts. Most of these portable heaters are rated at 1500 watts of heat then there is a blower motor. Being this is an electric heater it must be sized at 125% which will make the heater rated at 1875 watts.

A 20 amp receptacle can have 1900 watts plugged into them but we don’t have very many 20 amp receptacles in our homes. Even the 20 amp circuits will have 15 amp receptacles. Yes this is code compliant.

This very high load has cause something to burn loose in the circuit therefore you are now searching for that needle in a hay stack. To find the problem find out what is not working with the breaker off and try to figure out how the circuit was pulled from the panel to the last device served by that circuit. Open each and every box starting from the first one to the last one and check for voltage. Do not just look, check for voltage using both the neutral and the equipment grounding conductor.

Do this before looking for a broken cable as it will most likely be in an enclosure behind another receptacle, switch or light fixture.

Remember only can plug in a fire hazard into your receptacle. Wait a minute that was only you can prevent forest fires but I think you get the idea. Just in case you didn’t, throw that damn portable heater away before you wake up thinking you are in the pits of hell due to all the heat the fire is producing.

... The biggest cord and plug load that can be plugged into any 15 amp receptacle is 1440 watts. Most of these portable heaters are rated at 1500 watts of heat then there is a blower motor. Being this is an electric heater it must be sized at 125% which will make the heater rated at 1875 watts.

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If a corded appliance can draw more than 15 amps, shouldn't a 20 amp plug be required? (by UL or something?)

Cacher, I have examined and tested every device and every visible connection behind a device on that circuit. Next step is the attic, where I will hopefully find a junction box with a failed connection (or an electrocuted squirrel with romex between his teeth).

Jad, I agree, which is why I replaced one of the crumbling taped connections with a wire nut. But the large pig-tail had wires coming into it from three directions with no play at all, so they could not be made to fit into a wire nut. So, I taped the heck out of them. As for using the stabs, I'm as guilty as the electrician who used the stabs on the original outlets. I always tug on the wires to make sure they won't pull out, before I install them.

JW, I have very lousy hydronic baseboard heat here, and the space heaters keep my toes from freezing.

I always run my space heaters on low heat. Except, of course, this time, when I ran it on high heat, thinking that the worst thing that could happen is it would pop the breaker. Boy, was I wrong.

There are other splicing devices than wire nuts...it's just that wire nuts are usually cheaper...I'd find one and use that. Some have a series of holes with a screw that tightens down on the wire while connecting it to those adjacent.

I shut off all the breakers except for the bad circuit. Then I followed that cable in the attic with my non-contact volt tester, until it disappeared down a wall far away from where the power was out. I was about to give up, when later that day the lights came on and the outlets began working again (for a few minutes), even though the circuit I thought was bad had the breaker turned off (and the other breakers were turned on).

I was following the wrong cable! The outage was part of a larger circuit that contains 7 outlets and 3 light switches. The "red herring" circuit contains nothing. It is just power leading to behind a wall to no devices that I could find.

Once I determined the correct circuit, it was still tricky finding the bad outlet, because it had power, and there were no loose wires or signs of burning. It just didn't deliver any power to the other devices in the chain. Some internal defect in the receptacle.

The real villain in all of this is the painter, who painted over the breaker box and covered the labels. He also painted over all the outlets, which should have been replaced long before I moved in.

[This is a rental unit, but I have been doing all the maintenance, because the repair men they send out are unqualified and unprofessional.]

The bad outlet is the one used for the wall A/C, which is rated at 1050 watts. My guess is that the A/C over time had begun to burn something out in that receptacle, and the space heater finished the job.